An optical disk such as a Blu-ray Disc (registered trademark) and a DVD (Digital Versatile Disc) is known to be provided with a bar code-shaped recording region in a predetermined region of a disk inner peripheral side. This is called BCA (Burst Cutting Area).
This BCA has a radial pattern formed as a region having a different reflection rate, so that the BCA is a region from which information can be read without tracking. In addition, in particular, in optical disks manufactured in large volume, the BCA is used as a region to which information peculiar to a disk, e.g., information about a serial number, can be attached.
In the conventional BCA, the optical disk is completed as a result of the manufacturing steps, and thereafter, a serial number, disk information, and the like is written off-line by a BCA recording device, for each disk, to a further inner periphery of the signal region (for example, a region of a radius of 21 to 22 mm), so that each can be managed.
The BCA is a pattern in which the high reflection rate region and the low reflection rate region appear alternately when scanned in the track line direction, and information can be read from the level of the reflection light of each region. In order to form the low reflection rate region, the BCA recording device outputs high power laser, so that the region is formed by burning off the reflection film.